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Andrew Alden
8,128 followers -
Writer on geological subjects: KQED, blogs, books & whaddayagot?
Writer on geological subjects: KQED, blogs, books & whaddayagot?

8,128 followers
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Sibley Volcanic Regional Preserve is the site of a small volcanic center that was last active about 10 million years ago. After it fizzled out, the whole thing was gradually buried in younger sediment. Within the last few million years, the action of the…
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During the eight years I was surveying every sidewalk in Oakland, taking in the geology and geography as I went, I took thousands of pictures. Here’s a baker’s dozen of my favorite shots from the ancient alluvial fan that dominates central Oakland,…
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Lots of people love old photographs of familiar places, or old landmarks when they were new. I love old photos of Oakland because they show the land before it was paved over and/or forested. The early California photographer Carleton Watkins was…
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Once upon a time there was a thriving native encampment near the head of San Antonio Slough, tucked under bountiful oak trees in a valley with a permanent stream. Then the padres of New Spain put the natives behind walls to earn their bread with the sweat…
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Once upon a time, we used to produce a lot of our water from local wells, but for the last century we’ve retired them as the aquifers were drawn down or polluted. So I’m always surprised and intrigued to see wells still at work. This is on Willams Street…
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With all the construction going on around town, you’ll see lots of drill rigs taking geotechnical cores. This one was at work at 2330 Webster, where the Webster Alexan development will go. Just a few days earlier, a rig was collecting cores in the parking…
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Last week I lingered over Leona Creek, in the Leona Heights area, but there are three other streams in the land between Horseshoe Creek and Chimes Creek. I’ll label them on the watershed map from 1 to 3, putting the numerals where they enter culverts.…
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Over the years I’ve done a lot of poking around Leona Heights, the large hill looming over the south end of the Warren Freeway. You’d think I have a nice photo after all this time, but instead here’s a vertical view from Google Maps, terrain view. It…
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This five-mile urban hike is more of a terrain-and-streams ramble than a bedrock ramble. It climbs over 700 feet, winding through the watersheds that freshen Lake Merritt and traversing some of Piedmont’s wildest land. Although I’ve walked the route both…
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In December 2006, I read a series of news stories about a landslide in Fruitvale, on McKillop Road, that took out a house and threatened two more, so I checked it out and was so impressed I wrote it up for About.com. This house was the victim. And this…
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